Electric discharge device



Nov. 17, 1953 GERMER 2,659,835

I ELECTRIC DISCHARGE DEVICE Filed Jan. 20, 1951 INVENTOR. Edmund Germer ATZURNEY de i es a i com. ne ne t io el et pds Wire ma ned Patented Nov. 17, 1.953

UNITED r cries 3 335 E' T Q HABG PEVEQ ugHLQerrner,,Berlin-Wannsee,Germany, as-

anovi'a'. Chemical 85 Manufacturing e va'rk, N. J a corporationLofhl'eW JrSCy Application January 20, l 95 1, -Ser ia l No. 206,?75

,1 pag (01.

vent o relates to elect ic discha P ti la rdev c s- El ctri disc ar d ses ta l d ri Opera tionusuallybecauseo f fa'l re-of the electrodes i t i Y le aE isQ se i iie l iesbdt teed dveeta in construcsam with already existing auxiliary equipment such as damp sockets, reflectors, etc., without requ iring' alteration of such auxiliary qui mentu the ebiectsandva ou a tages will appear from the following detailed descriptiomtaken in connection with the accompanying drawing in which:

-Fig. 1 is a view, partly -i-n sectionof a discharge de-v-ice constructed according toth'einvention,

Fi 2 is an end view of the device shown in Fig. 1,

Fig. 3 is an end. view of the electrode structure of th device illustrated in Fig. 1, and 5 Fig. 4 is a sectional view of an end portion of a modified form of a lamp constructed in accordance with the invention.

Like numerals designate corresponding parts throughout the several views of the drawing.

Broadly stated, the invention resides in the provision in a vapor discharge device of a p1urality of electrodes and connecting them to the contact terminals of the device in a suitable manner, whereby upon failure of one electrode, or of a lead-in conductor, another electrode may be readily connected to the source of current and the device again be used as before the failure.

Referring now to Fig. l of said drawing, there is illustrated a lamp, constructed in accordance with the invention, having an envelope 5 of light transmissive material. If the lamp is designed to emit ultra-violet rays, its envelope is formed of quartz or other ultra-violet transmissiv materialv as ,iswell, understood by thoseskilledin the art. ,The lamp may be of the knownfluorescent type, :i. e.'it may have a coating of fluorescent material on its inner surface for converting invisible radiations to visible light. The lamp is preferably filled with rare gas and contains .a small amount of mercury or other vaporizable metal. Eachend of the tubular envelope .5 is closed by a flared seal-rstem'fi inknown fashion.

Stem t-has three lead-in conductors], ,8 and 9 vacuum tightly sealed .therein for supporting the two electrodes) and II withinthe envelope. The centerconductor =-'I is-v provided with a i head I2 on its inner end which may be suitably formed bybending the end of the fwire Ti as shown in thedrawing. Electrode II! isfastened to-theend ofwire conductor :8 and to the head It while electrode II is connected between head I2 .and conductor 9. "The-head VIZ separates the two electrodes .so :that heat from one of them .will not be d rectly conducted to the other during operation of the lamp. Electrodes I0 and I I may be of the known activated .0r.non.-activated types :d p ndingonthe use for which theilamp is designed.

eon each. en-dof the, tubular envelope v5 .is fixed an ;i n s u1ating cap I13. Instead of being inone piece as shown in thedrawingthe cap litmay comprise an insulating plate held against the sealedend of the glass ,tube .bya flanged sleeve that fits over the end of the tube. The cap I 3 is provided with two inwardly projecting sockets I4 and I5, and with an outwardly extending terminal pin I6, said sockets and pin being formed of an electrically conductive material. The center conductor I is electrically connected to the pin It while conductors B and 9 are connected to the sockets I4 and I5 respectively.

For connecting the sockets Id and I5 into the lamp circuit. the can I3 is provided with a plate 20 of insulating material having -nlugs 2! and 22, located on the same side of the plate 20 and dimensional to form a tight fit in the sockets I4 and I5. Also supported on the plate but on the opposite side of the plate from the sockets is a terminal pin 23 similar in construction. to the terminal pin IE. A suitable electrical conductor 24. connects the terminal pin 23 with the plug 22, the plate 2!! being recessed to accommodate the conductor 24 for permitting the plate 2!] to lie flush against the cap 53. The cap I3 may also be recessed as illustrated to accommodate the plate 20.

When the lamp, illustrated in Fig. 2 is connected into an electric circuit, current will pass between the terminal pins l6 and 23, through lead-in conductor 7, electrode ll, lead-in conductor 9, socket I5, plug 22, and conductor 24 which is connected to the terminal pin 23. The electrode ll will thus become heated and will cause an arc to form between it and an electrode located in the opposite end of the lamp, all as is well understood by those skilled in the art.

When the electrode ll fails for any reason as by being burned out or by becoming inactivated, if originally activated, it may be easily disconnected from the electric circuit and replaced by the electrode I by merely removing the plate 29 and inserting the plug 22 into the socket M, whereby current will pass through the lead-in conductor and the electrode to energize the electrode [9 in a manner similar to that described above for the electrode ll.

As is best shown in Fig. 3, each of the electrodes l0 and II, may be located nearer to the axis of the tubular envelope by bending the inner por-' tion of the center conductor 1 out of the plane of the conductors 3 and 8, whereby the electrodes l6 and l I lie substantially side by side, rather than in an end to end relation.

The invention is adapted for use in devices employing self-heated electrodes. Such devices require only one terminal pin on each end of the lamp, the pin being connected by a single lead-in conductor to an electrode, The modification illustrated in Fig. 4, shows a portion of a lamp constructed in accordance with the invention, and employing self-heated electrodes. Referring to Fig. 4 electrodes and 26 are supported on the lead-in conductors 2! and 28, representative the lead-in conductors 21 and 28, respectively, which in turn are connected to the sockets 29 and 30 respectively, in the end cap 3|. The end cap 3| is provided with a plate 32 having plugs 33 and 34 and terminal pin 35 similar in construction to the plate 20 described above. Switching from one electrode to another is eifected in the manner explained in the above description of Fig. 1.

It has been proposed heretofore to construct radio tubes, X-ray tubes, and incandescent lamps with supplementary filaments which could be connected in circuit upon failure of the first used filament. This, to my knowledge, has not, however, been done heretofore with electric discharge devices, and it has not been accomplished with the simplicity and effectiveness that characterize this invention.

While I have described the invention more specifically with reference to a mercury or other vapor lamp, which may be a low pressure lamp, e. g. a germicidal or fluorescent lamp, or a high pressure lamp, it Will be noted that the invention is equally applicable to other types of electric discharge devices having a gaseous or metal vapor filling, or both.

The foregoing disclosure is to be regarded as descriptive and illustrative only and not as restrictive or limitative of the invention, of which obviously an embodiment may be constructed without departing from the general scope herein indicated and denoted in the appended claim.

What I claim is:

Electrical discharge lamp comprising a tubular envelope of vitreous material, a rare gas and a small amount of vaporizable metal in said envelope, each end of said envelope having a pair of separate conductors sealed therethrough, a selfheating electrode on each of said conductors inside of said envelope, a cap positioned on each end of said envelope, said cap being recessed inwardly thereof, a pair of spaced electrically conductive sockets in said recess, one of said conductors on the outside of said envelope being connected to one of said sockets and the other of said conductors being connected to the other of said sockets, a movable nonconductive plate member fitted into said recess, a single terminal pin projecting outwardly of the outer surface of said plate member, a pair of plugs on the under surface of said plate member, each engageable with one of said sockets, a conductor on the under surface of said plate member alternately connectable between one and the other of said sockets and said terminal pin by movement of said plate member.

EDMUND GERMER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,411,679 Cox Nov. 26, 1946 2,513,091 Frohock June 27, 1950 

